| Russellite | |
| Category: | Tungstate minerals |
| Formula: | Bi2WO6 |
| Imasymbol: | Rll[1] |
| Strunz: | 4.DE.15 |
| System: | Orthorhombic |
| Class: | Pyramidal (mm2) H-M symbol: (mm2) |
| Symmetry: | Pca21 |
| Unit Cell: | a = 5.43 Å, b = 16.43 Å c = 5.45 Å; Z = 4 |
| Color: | Yellow-green, yellow |
| Habit: | Fine-grained, compact, massive |
| Mohs: | 3.5 |
| Refractive: | 2.17–2.51 |
| Opticalprop: | Biaxial (+) |
| Dispersion: | Relatively strong |
| Gravity: | 7.33–7.37 |
| References: | [2] [3] |
Russellite is a bismuth tungstate mineral with the chemical formula Bi2WO6.[4] It crystallizes in the orthorhombic crystal system. Russellite is yellow or yellow-green in color, with a Mohs hardness of .
Russellite is named for the mineralogist Sir Arthur Russell, and the type locality is the Castle-an-Dinas Mine, near St Columb Major in Cornwall, where it was found in 1938 in wolframite.[5] It occurs as a secondary alteration of other bismuth bearing minerals in tin−tungsten hydrothermal ore deposits, pegmatites and greisens. It typically occurs associated with native bismuth, bismuthinite, bismite, wolframite, ferberite, scheelite, ferritungstite, anthoinite, mpororoite, koechlinite, cassiterite, topaz, muscovite, tourmaline and quartz.[2]